Gradient meter



July 17, 192s. 1,617,220

R. AERNOUT, BARON VAN LYNDEN GRADIENT METER Filed Feb.10, 1927 4 sheezs-sneet 2 QM@ #M July v17, 1928.

R. AERNOUT, BARON VAN LYNDEN GRADIENT METER Filed Feb. 10, 1927 4 Sheets-Sheet 3 July 17, 192& 1,617,220

l l R. AERNOUT, BARON VAN LYNDEN GRADIENT METER Filed Feb.1o, 1921 4 sheets-sheet 4 l; wwf/VITO?? 1 y 33) ,//w f y W @12T Patented July 17,1928.

` ,UNIT ED sT AIT Es' PAT-Eur o FFicE.'

ROBERT AEIRJXTOU'JIl,` BARON VAN LYNDEN, OF LONDON, ENGLAND'.

GRADIENT (METER.

Application led February "1), 1927,` Serial No. 137,1243, and in Great Britain February 23, ,1926.

l This invention relates to gradient meters, clinometers and like instruments of the type covered by the present inventorsprior Let:- tcrs Patent of the United States of America No. 15561347. The improvements embodied in the present invention have` for their' object a` simplied construction more particularlyiwith respect to `the manner in which the `weighted member is mounted and-driven so as to effect automatically the necessary corrections Vfor errors due to the inertia of the gravity-actuated indicator.

The improved construction is designed to be employed for various. purposes and in different ways-on different types of moving bodies such as motor roadvehicles, aircraft or submarine vessels.

i According to this invention there is combined iwith a pendulum `and a weighted wheel, a mechanism `by means of which this wheel. is rotated so" that it will have'iniparted to it an acceleration or deceleration which is substantially proportional to any acceleration or deceleration of the body on which the instrument is mounted as this body moves over the ground or through the air or wat-er this driving mechanism comprising a shaft mounted coaxially with respect to the axis about which the pendulum swings and a second shaft driven by gearing from the first shaft. and wholly carried by and swinging with the pendulum. In one construction the second shaftcarries the weighted wheel this Wheel and the shaft being: mounted on and wholly carriedl by and swinging with the pendulum. In an alternative construction. the drive is transmitted from the firstshafft which is mounted coaxially with respectto `the axis about which the pendulum swings, to a secondl shaft driven by gcaring'from the first sha1, and whollyicarried by and swinging with the pendulum, while a third shaft which carries the weighted wheel vis driven by gearing from the second shaft and is also mounted coaxially with respect to the axis about which the pendulum swings. In either case a clutch device. is incorporated `in thermechanism by means of which the weighted wheel is driven this clutch `device `while normally transmitting the drive-to theweighted wheel being arranged to yield automatically in the event of unduev irregularities Vin the drive so as to prevent damage to the mechanism from these irregularities; Itfisfdesirable t-oprov ide on-the pendulum a weight ,Whose position on the pendulum may be adjusted `so as to permit of acompensating setting off the mechanism toV be effected. In order: to ob- -viate sudden movements ofthependulumyit 1s .convenient to provide adaslipoty device suitably connected to the pendulum.

The accompanyingr drawingsillustrate by i way of example alternative constructions whichmay be adopted in carryingr out the invention, these constructions beingifdesigned more particularly for use on motor rod vehicles. In these drawings f Figure l is a sectional elevationot one form ot' the apparatus as viewed from the baclr thereof, the section being-taken as non the line l-x-l in Figure 2 looltingin the direction ot thel arrows.V z

` Figure 2 isa side elevation of the appa,--

ratus partly inv section the section being taken on the line 2-2in `Figuire 1 looking lin the direction of the arrows. i i` Figure 3 is a sectional elevation somewhat similar to that shownlin Figure 1 but looking from the front ofthe-.apparatus and illustrating a n'ioditied construction. i

Figure dis a perspective view illustrating a method that` may be adopted conveniently in the mounting of a rotating shaft in the apparatus. n

Figure vfi-*transverse section on the line 5 5 in Figure G-or inFigure-T ill stratiug a modified form of the instrument shown in Figure Tl wherein the weightedwheel is carried wholly by the pendulum7 looking in the direction ot' the arrows. i

Y Figure Gis a sectional plan on the broken line G-G in Figure 5 looking' in the direction of the arrows. 1

Figure/ T is a ,section von theibrolen line 7--7 in Figure lookingiin the direction ofV gil) shape is provided 'to enclose the apparatus, this casing having a back plate A1 on which is mounted as far as practicable the 1nechanism, so that access thereto can be obtained readily by removing the back plate. In the front .of the casingr A is a window A2 through which `may be read the indications given by the gradient meter.

Projecting from the back plate A1 are two bracket members or `plates B and B1 which serve to support the principal parts of the apparatus. Suspended from these brackets Bv B1 bypivots such as C C1 of suitable construction is a U-shaped member constituting a pendulum this pendulum comprising a horizontal part D and two lateral arms, of which the one D1 isv straight and eX- tends substantially vertically throughout its whole length, while the other arm comprises two substantially' straight vertical portions D2 D2 connected by a horizontal portion D1. These late 'al arms D1 and D2 D4 D3 extend between the horizontal part D of the pendulum and thepvotsC C1. The part D2 of the onependulum arm is provided with a laterally extending lugl E having in it a slot E1 and a weight F of suitable shapeand dimensions is att-ached to the pendulum by a set screw F1 which passes through the slot E1. so that the `position of the weight F cany be adjusted for the purpose of compensation and general adjustment of the mechanism.

The pendulum arm D2 is also formed with alaterally extending lug' G which carries or is formed as a segmental plate G1 having a toothedrack G2. This 4rack meshes with a pinion H on :t rotatable spindle H1 which carries an indicating @drum H2. This` drum is arranged so that a scale marked on its periphery can be read through. the window A2 in the casing A. The spindle H1 is carried :it-its ends in suitable bearings respectively on a part of the bracket B1 and on another suitably arranged bracket which extends from the back` plate A1 but is not shown. in the dra-wingnfsV Projecting from the part D3 of the one pendulum arm is an arm J which extends towards :the back of the apparatus, that is to say, in the opposite direction to that in which extends the lugr G. A rod. orlink J1 ispivotally connected at one end to the end of the arm J and at the other end this rod J1 carries a piston J2 whiclrlies in and can reciprocate in a cylinder J 2 mounted on the back plate A1. This cylinder J3 and the piston J2 therein constitute a dashpot device the cylinder being filled with oil or other suitable liquid introduced conveniently through an opening,r in the back plate A which is sbownas being closed by a screwed plug J t;

A short shaft K is carried by and projects from the `face of a plate K1 which in turn is attached to one side of the bracket B.

The shaft K is positioned so that its axis coincides with the axis of the pivots C C1 about which the pendulum swings. A sleeve L is mounted and can rotate freely on the shaft K and has formed on its inner end a flange vface of the shoulder L1 by one end of a coiled spring N whose other end bears against the opposed face of the toothed wheel L2. Rotation is imparted to the sleeve L and toothed wheel L2 by means of a bevel pinion M1 mounted on the end of a short shaft M2 rotatably carried in a lufar A suitably formed on or carried by the back plate A1. The outer end of the shaft M2 is squared or otherwise shaped and adapted to be coupled to the end of a flexible driving shaft through which the mechanism may he driven from the driving `gear or road wheels of the vehicle on which the gradient meter is mountedthis drive being so arranged that the mechanism within the casing will be driven at a speed which is substzmtially proportional to the road speed of the vehicle or so that a weighted wheel driven by this mechanism will be rotated and have imparted to it an acceleration or deceleration which is substantially proportional to any acceleration or deceleration of the vehicle. Frictional engagement after the manner of a clutch is maintained between the opposed faces of the bevel wheel M and the shoulder L1 which are kept in contact by the spring N so that while the toothed wheel L2 willv be driven in the desired manner yet in the event of sudden shocks in the driving mechanism or irregularities in the torque, as for instance, if the road wheels of the vehicle skid and rotate suddenly at increased speed or il their rotation is suddenly checked, the frictionally engaging surfaces of the clutch device will slip and thus prevent the irregularities from being communicated to the toothed wheel L2 and to the mechanism driven thereby.

A weighted wheel O ol suitnbhI construction'is fixed on a shaft O1 which carries also a toothed pinion (J2 gearing with the triaithed wheel L2. This sha l't O1 is mounted on the pendulum so as to rotatofreely relatively to the pendulum and yet swinglr with the latter. A, convenient method of mounting the shaft O1 so as to reduce friction is to dispose the reduced ends of this shaft so that they rest and can rotate on the peripheries of two discs or rollers P P1 which are respectively carried rotatably on studs by the side members D1 and D2 ot the pendulum. The ends of the shaft are kept in place on the disc P P1 by inverted U-shaped members llU ISU

fil.

`Q`attached to the `inner faces of the penduwhich the end ofthe shaft rests constitutes in ede/ct a roller vbearing and thus enables frictional resistanceto lthe rotation of the shaft O1 to be reduced. The arrangement is such that where theapparaltus is mounted on a motor road vehiclethe weightedwheel O will be rotated for example constantlyV and at a speed which `is substantially proportional to the speed of the vehicle.` Thus 'fluctuations in this road speed which, ow

` ing to the inertia of anormal pendulum,

would cause inaccurate readings, will result in the present construction in corresponding accelerations or decelerations in the rotation of the wheel O and this willleffect automatically the necessary corrections in the pendulummovements j The apparatus as aboive described is mounted in a suitable position for example in the dashboard `of `a motor road vehicle with t-he window A2 inthe casing A ai-,

ranged ina convenient position for reading the indications given; The'shaft M2 is connected by a flexible drive device with the mechanismemployed for driving the speedometer or otherwise arranged' so that the drive will be transmitted from some part of the vehicle mechanism which will `rotate at a speed substantially proportional to the speed of the vehicle 'along the road. Then `in accordance with the road speed theweig'hted wheel l) will be rotated. y p y By movementofthe weight F on the pendulum it is possible to make Van adjustment which `will havethe effect of altering the inertia of the pendulum with relation to the 'inertia of the flywheel. Thus if it is found that the action ofthe flywheel isto` give an excess of compensation during accelerat-ion or deceleration, then by lowering the weight F on the pendulum,` the inertia of the penduluu'i is in` effect increased `and thus the inertia of the flywheel may be correctly balanced. y c

In order to set the instrument so as to give a zero reading when on the level, it is convenient to construct the casing A so that the whole instrumentmay be swung or tilted as for example about pivots pas-sing through lugs A* formed on the casing A.. The casing may then be fixed by a clamping screw or the swinging` movement may be carried out by means of an adjusting sci'elvsuib ablyarranged. It is to be noted that when setting the instrument so as `to give a Zero reading itis desirable to arrange that when the body on which it is mountcd is standing on the level, the instrument should give an indication as of a slight upward gradient, `forexamplefof the order of one half `per lthe pivot C2 which supports this arm.

cent, since as soon as the body is'in' motion,

the fric'tional resi-stance to rotation of the lweightedwheel O will cause the pendulum to `be moved slightly and to an extent sufficient to give a zero reading while the vehicle or other body on which the instrument is mounted is travelling on the level.

Vhen the vehicle is moving along a road, so long as the road surface is level the gradient meter willgive a Zero indication irrespective of acceleration or deceleration of the vehicle, any tendency of the pendulum to swing in either direction as a result of such acceleration or decelerationbeing counteracted by the inertia of the weighted `wheel O. Also as indicated, if there is any irregularity in the drive, as for example by reason of skidding of the road wheels, the clutch device in the driving mechanism will yield and these irregularities or shocks will not be communicated toj the weighted` wheel O or to the pendulum. On an" incline the pendulum will swing and by rotating the indicating drum H2 will give a substantially correct indication ofthe gradient, any errors in this indication which might tend to appear owing to the inertia of the pendulum being neutralized or automaticallycorrected by the inertia of the rotating wheel O.

-\ Referring to the' alternative construction illustrated in Figure 3, it will be seen here that the shaft G3 carrying the weighted wheel O4 is not `mounted on the `pendulum D5 but is arranged coaxially with the pivots C2 C3 about which the pendulum swings, while the drive is transmitted through an intermediate lshaft mounted on the pendulum. The pendulun'i comprises a single U- shaped member with a horizontal part D5 and lateral arms D D7 both these arms being conveniently straight and similar. .Au ad-- instable weight F2 is attached to the pendulum arm D" in a suitable manner the details of which are not shown in the drawing, but preferably a slot andv set screws F are em ployed, somewhat as described in connection with the construction shown in Figures l and 2. The casing of the apparatus is not shown in Figure 3 the back plate .A5 alone being indicated. Projecting from this bac-lc plate are two bracket members B2 and D one of these brackets B2 being arranged adjacent to thearm D of the pendulum and carrying The other bracket B3 is disposed in a suitably intermediate position between the arms D' and D of the pendulum and has fixed on the one face thereofthe flange or plate KE of the shaft K4 which carries the hollow driving shaft or sleeve L3. The Vouter end weighted roo lLZU

K5 of the shaft K4 is engaged by the second n lilo end the toothed wheel L4 and at the other end a worm wheel M3 which is engaged by a worm M4 on the shaft M5 through which the drive is transmitted to the apparatus.

In a bearing member R of suitable type and construction, which is disposed in some convenient manner on the horizontal member D5 of the pendulum, there is rotatably mounted a shaft S. On one end of this shaft is a pinion S1 which meshes with the toothed wheel L" while on the other end is a toothed wheel S5 which gears with a toothed pinion O5 through which rotation is imparted to the weighted wheel In this ease a slipping clutch device is conveniently arranged between the pinion and the Shaft O3 which carries the weighted wheel O". With this object the shaft O3 is provided with a. shoulder O5 against one tace of which bears the face of the pinion O5 which is loosely mounted on the shaft O5 but is constantly pressed against the shoulder or flange O5 by one end of the coiled spring N1 'whose opposite end bears against the tace of the weighted wheel O4. The opposed faces of the shoulder O5 and pinion O5 are suitably formed to effect the desired frictional engagement between these parts while permitting slip in the event of irregularities in the drive.

The shaft O3 is mounted on friction reducing bearingstormed and arranged conveniently in substantially the same way as described with reference to the construction shown in Figures l and 2. The reduced ends of the shaft O5 rest respectively on discs P2 and P5 of which the 1to1-mer is earried by the bracket B2 while the disc P5 is carried by the bracket B5. Inverted U shaped members Q2 attached respectively to the brackets B2 and B5 keep the ends ot' the shaft O5 in place on the upper edges ot' the dises P2 and In.

The apparatus operates in substantially the same way as that previously described and shown with reference to Figures l and 2. The drive is transmitted from the shaft M5 through the hollow1 shaft L3 and intermediate shaft S and gear wheels carried thereby to the pinion O5 and thence through the clutch device to the shaft O3 and weighted wheel OL which is thus rotated at a speed substantially proportional to the road .speed of the vehicle on which the apparatus is mounted. rIho inertia oi the wheel 0i* will correct automatically any errors which tend to arise from the inertia of the pendulum. The movements of the pendulum may be communicated to and indicated by a swinging or rotatable member which is not shown in Figure 3, but may be arranged in a manner somewhat similar to the indicating drum H2 in the construction shown and1 described with reference to Figures 1 an 2.

In the construction illustrated in Figures 5, G and 7 the apparatus comprises a cylindrical casing A5, having a rear wall A7 from which project two supporting brackets B4, B5, one, B5, of which is formed integral with a tubulin' boss or housing B5 carrying a driving shaft M. Supported in bearings C4, C5 on the brackets B5, B5 is a pendulum D5. This pendulum comprises a horizontal portion I)S and two vertical portions D", D15. Rigidly mounted on the bracket B5 and arranged coaxially with the pivot bearings C, C5 ot the pendulum is a short shaft K on. which is adapted to rotate freely a sleeve or hollow sha-ft L5 having a flange L0 against which is pressed bv a spring M2 a lbevel wheel M5. The bevel wheel M" engages with y a bevel wheel M5 rigidly mounted on the end of the driving shaft M In `this way the bevel wheel M" is frictionally connected t0 the sleeve L5 by reason of its being pressed against the flange L The sleeve L5 is held in place on the shaft K by means of a screwthreaded member U engaging the interior of the shaft K as shown.

Also mounted on the sleeveL5 is a pinion L5 which engages with apinion O5 on a shaft O5 siipported in suitable bearings on the portions D, D10 of the pendulum D and carrying also the weighted wheel O5.`

'lhe shaft V(l5 is conveniently supported in irietiou reducing bearings each comprisinfv three disc-like members I, P5 and l thi rims of which engage the reduced ends O1" ot the shaft OS, iach ot these disc-like members being suppm-ted in bearings I carried by the parts Il, D of the pendulum D5.

The apparatus yoinfraterf; in substantially the same way as that reviously described and shown with reference to Figurel and 2. The drive is transmitted from the sha'lt M5 through the bevel wheels M5, M? and the friction clutch device constituted bv the bevel wheel M7 being pressed into edntaet with the flange L5 to the hollow sleeve L5 and thence through the gear wheels L5, (Y to the shaft O5 and weighted wheel O5 which is thus rotated at a speed substantially proportional to the road speed ot the vehicle on which the apparatus is mounted. The inertia ofthe wheel O5 will temliautomatically to prevent errors arising from the inertia ot the pendulum.

The movements ol the pendulum may be communicated to an indicating needle or the like in various ways but in the construction shown the upper end ot' the member D of the pendulum is provided with two lateral extensions D11. D12 to one, D15, of which `is connected by a bolt G5, a toothed quadrant G4. The teeth G5 of the quadrant (i4 engage with a pinion H5 rigidly mounted on a. shaft il* which is `carried 1n bearings in a suitable support H5 mounted on a bar A8 extending across the front of the casingA".

submarine, the drive may be takenoif the propeller shaft. Y

It maybe pointed out that whenused on air craft or ona submarine, it may not be practically possible to arrange for the rotational speed of the weighted wheel to be strictly proportional to the speed of the oody on which the instrument is mounted owing to the slip of the propeller, turbine or other device that would be used to drive the weighted wheel. Nevertheless the desired correction of the pendulum can be effected in the mannerdescribed since the speed at which the flywheel is driven will be in delinite relation to the movement of the body on which it is mounted through the air or water. i

What I claim as my invention and desire to secure by Letters Patent s:-

l. In a gradient meter mounted on a moving body, the combination of a gravity-actuated member, an indicator operatively connected to the gravity actuated member, a shaft mounted coaxially with respect to the axis about which the gravity-actuated member moves, mechanism forrotating this shaft at a speed proportional to that of the moving body, a driven shaft carried wholly by and swinging with the gravity-actuated member, transmission gearing connecting these two shafts, and a weighted wheel operatively connected to the driven shaft so that its speed is proportional to the speed of such shaft.`

2. In a gradient meter mounted on a moving body, the combination of a pendulum, an indicating device actuated by the pendulum, a weighted wheel, and mechanism for rotating this wheel at a speed proportional to that of the moving body, this mechanism including a driving shaft mounted coaxially with respect to the axis about which the pendulum swings, a driven shaft carried wholly by and swinging with the pendulum, and operative driving connections between the two shafts and between the driven shaft and the weighted wheel whereby the Weighted wheel is caused to rotate at a speed proportional to that of the driven shaft.

3. In a gradient meter mounted on a moving body, the combination of a gravity-actuated member, an indicator ope atively connected to the gravity actuated member, a weighted wheel, and mechanism for rotating this wheel including a driving shaft mounted coaxially with respect to the axis about which the gravity-actuated member moves, means for rotating said drive shaft at a speed proportional to that of the moving body, a driven shaft carried wholly by and swinging with the gravity-actuated member, operative driving connections between the two shafts and between the driven shaft and the weighted wheel whereby the weighted wheel is caused to rotate at a speed proporactuated member moves, mechanism for rotat-ing this shaft at a speed proportional to that of the moving body, a driven shaft carried wholly by and swinging with the gravity-actuated member, transmission gearing connecting-these two shafts, and a weighted wheel operatively connected to the driven shaft so that its'speed'is proportional to the speed of such shaft.

5. In a gradient meter mounted on a moving body, the combination of a. gravity-actuated member, an indicator operatively connected to the gravity actuated member, a dashpot device, an operative connection hetween the dashpot device and the member,

a weighted wheel, and mechanism for rotating this wheel at a speed proportional to that of the moving body, this mechanism including a driving shaft mounted coaxially with respect to the axis about which the gravityactuated member moves, means for rotating said drive shaft at a speed proportional to that of the moving body, a driven shaft carried wholly by and swinging with the gravity-actuated member, and operative driving connections between the two shafts and between the driven shaft and the weighted wheel whereby the weighted wheel is caused to rotate at a speed proportional to that of the driven shaft.

6. In a gradient meter mounted on a moving body, the combination of a pendulum, an indicating device actuated from the pendulunn,mechanism for altering the setting of the indicating device relatively to the )endulum a weighted wheel and mechanism for rotating this wheel at a. speed prgportional to that of the moving body, this mechanism including a driving shaft mounted coaxially with respect to the axis about which the. pendulum swings, a driven shaft carried wholly by and swinging with, the pendulum, and operative driving connections between the two shafts and between the driven shaft and the weighted wheel whereby the weighted wheel is caused to rotate at a speed proportional to that of the driven shaft.

7. In a gradient meter mounted on a moving body, the combination of a pendulum, an indicating device actuated from the pendulum, a friction clutch device between the pendulum and the indicating device, means for holding the pendulum and for moving the indicating device relatively thereto, a

lill

and the weighted wheel, and mechanism for rotating this wheel at a speed proportional to that of thek moving body, this mechanisin including a driving shaft mounted coaxially with respect to the axis about which the pendulum swings, a driven shaft carried wholly by and swinging with the peiiduhinn, and operative driving connections between the two shafts and between the driven shaft and the weighted wheel whereby the weighted wheel is caused to rotate at a speed pro-- portional to that of the driven shaft.

8. In a gradient meter mounted on a moving body, the combination of a pendulum, a weight adjustably mounted on the pendulum, an indicating device actuated from the pendulum, mechanism for altering the setting of the indicating device relatively to the pendulum, a weighted wheel, and mechanism for rotating this wheel at a speed proportional to that of the moving body, this mechanism including a driving shaft mounted coaxially with respect to the axis about which the pendulum swings, a driven shaft carried wholly by and swinging with the pendulum, and operative driving connections between the two shafts and between the driven shaft and the weighted wheel whereby the weighted wheel is caused to rotate at a speed proportional to that of the driven shaft.

9. In a gradient meter mounted on a moving body, the combination of a. pendulun'i, a weight adjustably mounted on the pendulum, an indicating device actuated from the pendulum, a friction clutch device between the pendulum and the indicating device, means for holding the pendulum and for moving the indicating device relatively thereto, al weighted wheel, and mechanism for rotating this wheel at a speed proportional to that of the moving body, this mechanism including a driving shaft mounted coaXially with respect to the axis about which the pendulum swings, a driven shaft carried wholly by and swinging with the pendulum,

and operative driving connections between the two shafts and between the driven shaft weighted wheel whereby the Weighted wheel is caused to rotate at a speed proportional to that of the driven i shaft.

l0.` In a gradient meter mounted on a moving body, the combination of a gravityactuated member, an indicator operatively Y connected to the gravity actuated member,

a driving shaft mounted coaXially with respect to the axis about which the gravityactuated member' moves, mechanism for rotating this shaft at a speed proportional to that of the moving body, a driven shaft carried wholly by and swinging with the gravity-actuated member, a weighted wheel rigidly mounted on the .driven shaft, and

transmission gearing connecting the vdriving and driven shafts.

ll. In a gradient meter mounted on a moving body, the combination of a gravityactuatcd gradient member, an indicator operatively connected to the gravity actuated member, an adjustable weight mounted on said gravity-actuated member, a driving shaftniounted coaxially with respect to the airis about which the gravity-actuated meinber moves, mechanism for rotating this shaft at a speed proportional to that of the moving body, a` driven shaft carried wholly byV and swinging with the gravity-actuated member, a weighted wheel rigidly mounted on the driven shaft, and transmission gearing' connecting the driving and driven shafts.

12. In a gradient meter mounted on a moving body, the combination of a gravityactuated gradient member, an indicator operatively connected to the gravity lactuated member, a dashpot device, :inoperative con- `nection between the dashpot device and the said gravity-actuated member, a driving shaft mounted coaxially with respect to the anis about which the gravity-actuated member moves, mechanism for rotating this shaft at a speed proportional to that of the moving body, a driven shaft carried wholly by and swinging with the gravity-actuated member, a weighted wheel rigidly mounted on the driven shaft, and transmission gearconnecting the driving and driven shafts.

13. In a. gradient meter mounted on a moving body, the combination of a pendulum, an indicating device actuated from the pendulum, a friction clutch device between the pendulum and the indicator, means for holding the pendulum and for moving the indicator relatively thereto, a driving` shaft mounted coaxially with respect to the axis about which thependulum swings, a driving member for rotating this shaft at a speed proportional to that of the moving body, a driven shaft carried wholly by and swinging with the pendulum, a weighted wheel mounted on this driven shaft, and transmislll) sion gearing connecting the driving and y Weighted wheel mounted on this driven shaft, and transmission gearing connecting the driving and driven shafts.

15. In a gradient meter mounted on a moving body the combination ot' aA gravity actuated member, the position of which indeates the gradient, a shaft mounted eoaxiaily with respect to the axis about which the gravity actuated member moves, mechanism for rotating this shaft at a speed proportional to that of the moving body, a driven to the driven shaft so that its speed is proportional to the speed of such shaftY` In testinion whereof have sinned m 'i naine to this speeiieation.

ROBERT AERNUT, BARN van LYNDEN. 

